[src/trunk]: src/sys Revert most of the previous change.

[dsl <dsl%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/74d5a4d57960
branches:  trunk
changeset: 749959:74d5a4d57960
user:      dsl <dsl%NetBSD.org@localhost>
date:      Sun Dec 13 18:27:02 2009 +0000

description:
Revert most of the previous change.
Only one fd needs clobbering, not all fds that reference the pipe.
This may be what ad@ realised when he tried to add the same code to
sockets. Unfixes part of PR/26567.

diffstat:

 sys/kern/sys_pipe.c |  26 ++++++++++----------------
 sys/sys/pipe.h      |   3 +--
 2 files changed, 11 insertions(+), 18 deletions(-)

diffs (80 lines):

diff -r 71f552a501e6 -r 74d5a4d57960 sys/kern/sys_pipe.c
--- a/sys/kern/sys_pipe.c       Sun Dec 13 17:58:27 2009 +0000
+++ b/sys/kern/sys_pipe.c       Sun Dec 13 18:27:02 2009 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: sys_pipe.c,v 1.123 2009/12/12 21:28:04 dsl Exp $       */
+/*     $NetBSD: sys_pipe.c,v 1.124 2009/12/13 18:27:02 dsl Exp $       */
 
 /*-
  * Copyright (c) 2003, 2007, 2008, 2009 The NetBSD Foundation, Inc.
@@ -68,7 +68,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: sys_pipe.c,v 1.123 2009/12/12 21:28:04 dsl Exp $");
+__KERNEL_RCSID(0, "$NetBSD: sys_pipe.c,v 1.124 2009/12/13 18:27:02 dsl Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -542,12 +542,8 @@
                 * Detect EOF condition.
                 * Read returns 0 on EOF, no need to set error.
                 */
-               if (rpipe->pipe_state & (PIPE_EOF | PIPE_ABORTED)) {
-                       if (rpipe->pipe_state & PIPE_ABORTED)
-                               /* Another thread has called close() */
-                               error = EBADF;
+               if (rpipe->pipe_state & PIPE_EOF)
                        break;
-               }
 
                /*
                 * Don't block on non-blocking I/O.
@@ -984,13 +980,6 @@
                                break;
                        }
 
-                       if (wpipe->pipe_state & PIPE_ABORTED) {
-                               /* Another thread has called close() */
-                               if (uio->uio_resid == 0)
-                                       error = EBADF;
-                               break;
-                       }
-
                        /*
                         * We have no more space and have something to offer,
                         * wake up select/poll.
@@ -1220,9 +1209,14 @@
 {
        struct pipe *pipe = fp->f_data;
 
-       /* Unblock blocked reads/writes - they will return EBADF. */
+       /*
+        * Unblock blocked reads/writes in order to allow close() to complete.
+        * This isn't going to work yet!
+        * The underlying problem is that only the 'fd' in question needs
+        * its operations terminating, the pipe itself my be open via
+        * other fd.
+        */
        mutex_enter(pipe->pipe_lock);
-       pipe->pipe_state |= PIPE_ABORTED;
        cv_broadcast(&pipe->pipe_rcv);
        cv_broadcast(&pipe->pipe_wcv);
        mutex_exit(pipe->pipe_lock);
diff -r 71f552a501e6 -r 74d5a4d57960 sys/sys/pipe.h
--- a/sys/sys/pipe.h    Sun Dec 13 17:58:27 2009 +0000
+++ b/sys/sys/pipe.h    Sun Dec 13 18:27:02 2009 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: pipe.h,v 1.30 2009/12/12 21:28:04 dsl Exp $ */
+/* $NetBSD: pipe.h,v 1.31 2009/12/13 18:27:02 dsl Exp $ */
 
 /*
  * Copyright (c) 1996 John S. Dyson
@@ -96,7 +96,6 @@
                                   pointers/data. */
 #define        PIPE_LWANT      0x200   /* Process wants exclusive access to
                                   pointers/data. */
-#define        PIPE_ABORTED    0x400   /* fo_abort()ed, unblock read/write */
 
 /*
  * Per-pipe data structure.